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This study focuses on comparing the efficiency of commercially available TiO 2 (P25) with synthesized TiO 2 nanoparticles (TiO 2 NP) impregnated in nonmodified cellulose membranes, specifically targeting the degradation of Indigo Carmine (IC) dye. We developed a novel method to enhance the interaction between cellulose and TiO 2 , thereby improving efficiency and reusability. This involves dissolving microcrystalline cellulose in 1-butyl-3-methylimidazolium chloride (BMImCl) and dispersing the TiO 2 samples within this solution. The resulting cellulose membrane embedded with TiO 2 nanoparticles (TiO 2 NP) exhibited a higher adsorption capacity and greater photocatalytic efficiency against IC compared to that of P25. This improvement is attributed to the larger surface area and increased reactivity of the synthesized TiO 2 NPs. Furthermore, the CEL_TiO 2 NP membranes demonstrated excellent stability and reusability, maintaining their catalytic efficiency over multiple cycles. This study presents new opportunities for developing efficient, reusable photocatalytic materials for environmental remediation using eco-friendly cellulose., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Aim: We evaluated the effects of the incorporation of zinc oxide (ZnO) nanoparticles in a mesoporous matrix, aiming to improve the textural, structural and morphological properties and verify their safety so that they can be applied in sunscreen cosmetics., Materials and Methods: ZnO nano-particles were incorporated into an ordered mesoporous silica matrix known as Santa Barbara Amorphous-15 (SBA-15), using post-synthesis methodology. The resulting nanocomposites were characterized using X-ray diffraction, small angle X-ray scattering, N2 adsorption-desorption isotherms, Fourier transform infrared spectroscopy, scanning electron microscopy and predicted in vitro sun protector factor (SPF) estimation. Effectiveness and safety were evaluated by antimicrobial activity, in vitro cell toxicity and non-invasive multi-photon tomography with fluorescence lifetime imaging., Results: The structure of the nanocomposites was similar to that of SBA-15, with little perturbation caused by ZnO incorporation. Nanocomposites had an increased in vitro SPF, reduced cytotoxic activity and favourable antimicrobial properties compared to ZnO. ZnO:SBA-15 nanocomposites exhibited no measurable toxicity when applied to human skin in vivo., Conclusion: Due to their suitable physicochemical properties and improved safety compared to bare ZnO nanoparticles, the ZnO:SBA-15 nanocomposites show promise for use in cosmetic applications., (© 2018 S. Karger AG, Basel.)

In this work we analyze the effect of adding CuO to a NiO/Ce 0.9 Zr 0.1 O 2 oxide by in situ X-ray absorption near-edge structure XANES technique in Ce L3, Ni K and Cu K absorption edges in terms of sample reducibility and catalytic activity. The oxidation states of Ce, Ni and Cu cations are followed up during temperature programmed reduction (TPR) experiments in diluted hydrogen and during catalytic tests for partial oxidation of methane (POM) reaction. Redox behavior was correlated to conventional fixed bed reactor results. The effect of firing temperature, crystallite size, CeO 2 -ZrO 2 support and the presence of Cu and/or Ni as an active phase is also analyzed. Results showed a beneficial effect of CuO addition in terms of Ce and Ni reduction. A stronger interaction of NiO species with the support was revealed upon analysis of XANES reduction profiles in sample NiO/ZDC in contrast to bimetallic CuO-NiO/ZDC sample. Reduction onset temperature was found to depend on Ni crystallite size, being markedly promoted when samples exhibited low values of crystallite size both in supported and non-supported CuO-NiO species. In situ catalytic experiments for partial oxidation of methane showed a clear interplay between the redox behavior from the Ce in the CeO 2 -ZrO 2 support and the Ni from the active phase. Sample NiO/ZDC exhibited a continuous reduction of Ce cations in CH 4  : O 2 feed flow, carbon formation was detected in X-ray Powder Diffraction (XPD) patterns and Ni re-oxidation was found to take place, clear indications of catalyst deactivation. In contrast, sample CuO-NiO/Ce 0.9 Zr 0.1 O 2 displayed a slight re-oxidation of Ce and no re-oxidation of Ni altogether with the suppression of carbon formation., Competing Interests: The authors state that there are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)